LEVEL DENSITY PARAMETERS FOR THE BACK-SHIFTED FERMI-GAS MODEL IN MASS RANGE A FROM 24 TO 250

Authors & Affiliations

Plyaskin V.I., Kosilov R.A.
Institute of Atomic Energy, Obninsk, Russia

Abstract

The parameters α and def for the back shifted Fermi gas model are determined for 1224 nuclei. For 272 nuclei the parameters are determined from experimental data on cumulative numbers of low-lying levels and the average spacing between neutron resonances. For the rest nuclei the def parameter was determined from cumulative numbers of low-lying levels and values of α parameter obtained by the way of interpolation of data for 272 nuclei. The formula for the account of the damping of the shell effect at high excitation energies is suggested. A comparison is given with previous results and different experimental data on level densities.

Keywords
Fermi gas model, cumulative numbers of low-lying levels, the parameters α and def, the damping of the shell effect

Article Text (PDF, in English, Translated by IAEA)

References

UDC 539.172

Problems of Atomic Science and Technology. Series: Nuclear Constants", issue 1, 1999